US stocks closed at their lowest level since early October on Wednesday, weighed down by fresh concerns over China and slower global growth and as energy shares tumbled with oil prices.
Shares of oil majors Exxon and Chevron fell and the energy index dropped 3.6 per cent as oil prices plunged below $35 a barrel.
Apple briefly dipped below $100 for the first time in nearly five months following reports of slowing shipments of the company's iPhone 6S and 6S Plus models. The stock, which ended down 2.0 per cent at $100.70, was the biggest drag on both the S&P 500 and Nasdaq.
Against the trend, Netflix ended up 9.0 per cent after announcing its video streaming service was now live in more than 130 countries.
Weak data from China triggered declines in global equities markets on Monday, with the Dow recording its worst first day of the year since 2008.
The People's Bank of China on Wednesday stepped in again to weaken the yuan, raising fears that the country's economy was even weaker than had been expected.
"The big influence continues to be concerns about what's going on in China," said Stephen Massocca, chief investment officer at Wedbush Equity Management LLC in San Francisco.
"I think there's this theory going around that the global economy is going to slow greatly, driven by a large slowdown in China."
Adding to investors' nervousness was North Korea's announcement that it had successfully tested a hydrogen bomb. The United States and weapons experts voiced doubt the device was as advanced as claimed.
The Dow Jones industrial average ended down 252.15 points, or 1.47 per cent, to 16,906.51, the S&P 500 lost 26.45 points, or 1.31 per cent, to 1,990.26 and the Nasdaq Composite dropped 55.67 points, or 1.14 per cent, to 4,835.77.
Also in China, a survey showed that the country's services sector expanded at its slowest pace in 17 months in December.
US stocks briefly extended losses in afternoon trading after the Federal Reserve published its minutes from the last policy meeting in December. They showed policymakers decided to raise interest rates last month after almost all of them gained confidence inflation was poised to rise, but some voiced worries inflation could get stuck at dangerously low levels.
The CBOE Volatility Index, the market's favoured gauge of Wall Street anxiety, ended up 6.5 per cent to 20.59, but well off the high of 23.36 touched on Monday.
"We haven't really seen a major pick-up in volume to the downside. That shows that we are not seeing a lot of people panicking and trying to get out," said Scott Fullman, chief strategist at Revere Securities Corp.
US economic data earlier Wednesday showed private employers added 257,000 jobs, ahead of expectations. The US government's non-farm payroll report is due on Friday.
Chipotle fell 5.0 per cent to $426.67. The company was served with a grand jury subpoena in relation to a criminal investigation into a norovirus contamination at one of its restaurants.
About 8.2 billion shares changed hands on US exchanges, above the 7.1 billion daily average for the past 20 trading days, according to Thomson Reuters data.
NYSE declining issues outnumbered advancing ones 2,314 to 779, for a 2.97-to-1 ratio; on the Nasdaq, 2,019 issues fell and 812 advanced, for a 2.49-to-1 ratio favouring decliners.
The S&P 500 posted two new 52-week highs and 46 lows; the Nasdaq recorded 29 new highs and 132 lows.